This invention relates to food products which can be cooked or reheated using a microwave oven. The invention relates particularly but not exclusively to foodstuffs comprising a core and a coating surrounding the core, for example a battered or breaded product. The invention also relates to non-coated food products and to ingredients for food products. This invention also includes products which may be cooked or reheated in a conventional thermal oven, grill or shallow or deep fried.
Many food materials, for example natural muscle of poultry, fish or red meat or vegetable or processed foods contain a large percentage of water. Most fresh foods contain more than 60% water. Some of this water is bound, that is tightly attached to the constituent cells. The remaining mobile water is available and can be frozen. If a food product is frozen to a core temperature of between −1° C. and −30° C. or lower and is placed and irradiated in a microwave oven, the microwave energy will be primarily absorbed by the frozen available water. Whereas in conventional cooking heat is applied from the exterior, in microwave cooking heat is generated from within. The process of heating can be very rapid so that available water is converted into steam. When a food product is allowed to stand after heating in a microwave oven, water can continue to be expelled from the product. This is particularly noticeable for example when heating frozen fish muscle. The loss of water causes any food coating, particularly a batter, pastry or breadcrumb coating to become soggy and unpalatable. In addition the core of the substrate may become dry due to the loss of water.
Attempts have been made to limit the escape of moisture during microwave cooking by coating the product with a composition which forms an impermeable film. This is unsatisfactory because the natural distribution of water within the coated product is lost through any coating as steam and due to internal pressure. Furthermore an impenetrable coating or film is detrimental to the taste and mouth feel of the product.
WO97/03572 discloses a method of stabilising a microwave cookable or reheatable food material by impregnation of the product with a stabiliser composition comprising cellulose gum, modified starch, polydextrose, xanthan gum, egg albumen and pea starch.